A variety of machines are known for loading a use tape, e.g., a magnetic recording tape, onto hubs or into cassettes. Such machines are commonly known as "cassette loaders", "tape loaders", "tape winders" or "tape winding and splicing machines". They employ various types of splicing block assemblies for use in supporting tape which is to be spliced. The term "splicing block assembly" is sometimes called a "splicing block head" or a "shift block assembly". Examples of machines showing different splicing block assemblies are illustrated by U.S. Pat. Nos. 3,637,153, 3,737,358, 3,825,461, 3,997,123, 4,061,286, 4,062,719, 4,512,904, 4,486,262 and 4,682,742. The above-identified patents illustrate machines for loading magnetic tape into Philips-type audio cassettes and video cassettes, e.g., VHS, Beta and 8 mm cassettes. The audio cassettes and the video tape cassettes are similar in that the loaded cassettes consist of a cassette case containing two rotatable spools or hubs, a leader tape attached to each spool or hub, and a predetermined length of magnetic recording tape having its ends spliced to the two leaders. VHS and Beta-type video cassettes are substantially larger than Philips-type audio cassettes and differ therefrom in that they have (1) a pivoted door which conceals the recording tape when the cassette is not in use, (2) means for releasably locking the door, and (3) means for releasably locking the hubs against rotation. The 8 mm type video cassettes are close in size to the Philips-type cassettes, but they also have a pivoted door which conceals the tape when the cassette is not in use, and means for releasably locking the door. Another more recent form of cassette is the so-called RDAT cassette, which is smaller in size than the 8 mm video cassette and is used primarily for digital audio recording on magnetic tape. The RDAT cassettes have a door which is opened when the cassette is to be used.
The manufacture of loaded audio or video cassettes is similar in that the common practice is to start with a C-Zero ("C-0") cassette, i.e., a cassette that consists of a cassette case with the two hubs and a length of leader tape having one end connected to one hub and the other end connected to the second hub. These C-Zero cassettes are then filled with blank or prerecorded tape by means of automatic loading machines of the type known as in-cassette tape loaders. In some quarters the term "V-Zero" ("V-0") is used to identify an empty video cassette. However, more commonly the term "C-Zero" applies to both audio and video cassettes.
The procedure for loading magnetic tape into "C-0" audio and video cassettes comprises the following steps: (1) withdrawing a selected length of leader tape from the C-Zero cassette; (2) cutting the leader tape in two so as to form first and second leaders; (3) splicing the leading end of the magnetic tape to be wound into the cassette to the first leader; (4) rotating the hub to which the first leader is connected so as to wind a given length of magnetic tape onto that hub; (5) terminating winding of magnetic tape onto the first hub; (6) cutting the wound magnetic tape at a selected point outside of the cassette; (7) splicing the trailing end of the given length of magnetic tape to the second leader attached to the other hub; (8) winding the trailing end of the given length of magnetic tape and the second leader into the cassette; and (9) ejecting the loaded cassette from the cassette loader and replacing it with a new C-Zero cassette.
In the most common tape loaders, a splicing block assembly is required for the purpose of supporting and guiding the leading end of the tape to be wound and also the withdrawn leader from the cassette, so as to permit the leader and the magnetic tape to be cut at appropriate points in the cycle of operation and also to permit the leading and trailing ends of the magnetic tape to be spliced to the two leaders that are formed when the withdrawn leader is cut in two. The most common forms of splicing block assemblies comprise two or three splicing blocks. In the case of a splicing block assembly having two splicing blocks, one of the splicing blocks is movable and the other is stationary, and the movable splicing block has two parallel grooves for holding one of the two leaders and the magnetic tape to be wound and the stationary splicing block has another groove for holding the second leader. In the case where the splicing block assembly comprises three blocks, one block is usually stationary and the other two blocks are movable, and each of the blocks has its own track for supporting a leader tape or a magnetic tape to be wound into a cassette. Such forms of splicing head assemblies are illustrated by the patents mentioned hereinabove.
Audio cassettes are the easiest to load because the C-Zero audio cassettes have a relatively long leader. As a consequence, the space and position requirements of the splicing block assembly in an audio tape loader are less stringent than is the case with video cassettes. The VHS and Beta-type video cassettes have a relatively short leader, with the result that the splicing block head must be able to accommodate the shorter leader. The advent of the 8 mm video cassette was significant in that its leader was much shorter than the leader in the larger size VHS or Beta video cassettes. The leader of an 8 mm video cassette is only about 150 mm long from hub to hub. As a consequence, the splicing block assembly for an 8 mm video cassette loader machine must be able to accommodate a much shorter leader than is the case with machines for loading the larger size VHS or Beta video cassettes.
The advent of the RDAT cassette presents even more severe problems. The industry-recommended standard specifications for RDAT cassettes calls for a leader having a length of approximately 60 mm .+-.5 mm. This relatively short leader tape complicates the loading of RDAT cassettes. While some loading machine customers may accept RDAT leaders that are longer than the industry standard, machines are still required to load RDAT cassettes according to the industry standard specifications. The short length of available leader tape makes it impossible or difficult to load magnetic tape into RDAT cassettes using splicing head assemblies patterned after those heretofore used to load audio cassettes or VHS or Beta or 8 mm format video cassettes, so as to conform to the industry-accepted standard specifications and also to the requirements of individual manufacturers regarding quality, speed and reliability.